[unreadable] Our objective is to develop a new biomaterial, a salmon fibrin gel, that will bridge injured CNS tissue, support and promote axonal sprouting and growth, and deliver neurotrophic factors and cells. Aim #1 is to determine the factors, biochemical and mechanical, that promote neuronal survival and outgrowth in salmon fibrin gels. Since other proteins, FXIII, fibronectin, and plasminogen are associated with or co-purify with fish fibrinogen, they will be separated, purified, and depleted or supplemented to optimize the gel composition. The bioactivity of these proteins will be assessed by survival, neuronal production, and neurite outgrowth of mouse neurons implanted in the gels. Aim #2 is to determine if survival and neurite outgrowth in rat primary neurons, and differentiation in rat neural stem cells is augmented in the salmon gels. Rats are a common surgical model of human spinal cord injury, and the animal of choice for Phase II in vivo studies. The optimized gel from Aim #1 will be implanted with rat neural cells, and results assessed as in Aim #1. A biomaterial that promotes growth and connectivity of transplanted or endogenous neurons would be an important tool in neurosurgery. Identification of the growth-promoting molecule(s) in that material could offer new therapies for CNS injury and disease. [unreadable] [unreadable]